Yep, the required files were included. I think I've found the problem, and I'm not sure if it's a ST bug, but it's definitely a change. I have a custom proxy, which uses a custom reader. In my store, I use this custom proxy, and configure some values for the custom reader:

I actually solved this by "hacking" a bit. Basically I created a null reader, as in Ext.data.Reader.null (and same for proxy) - simply extending these on the core functionality. Got it all working now.

it is horrible indeed. We are testing the new beta (ST 2.1) but likely will wait for a general availability release before proceeding, hoping the bug will be fixed. Then again, I'll play around with this a bit more, perhaps can solve more elegantly indeed